Advances in MRI-guided precision radiotherapy

Magnetic resonance imaging (MRI) is becoming increasingly important in precision radiotherapy owing to its excellent soft-tissue contrast and versatile scan options. Many recent advances in MRI have been shown to be promising for MRI-guided radiotherapy and for improved treatment outcomes. This paper summarizes these advances into six sections: MRI simulators, MRI-linear accelerator hybrid machines, MRI-only workflow, four-dimensional MRI, MRI-based radiomics, and magnetic resonance fingerprinting. These techniques can be implemented before, during, or after radiotherapy for various precision radiotherapy applications, such as tumor delineation, tumor motion management, treatment adaptation, and clinical decision making. For each of these techniques, this paper describes its technical details and discusses its clinical benefits and challenges.